Combustion of gas

[205389184]

Will the combustion of gas always be spontaneous?

[Sebastian Lee 1L]

Under standard conditions, the combustion of gas is most likely spontaneous since you would usually be releasing heat (-delta H) and increasing entropy (+delta S). However, I wouldn't say that combustion is always spontaneous, especially depending on non-standard conditions. For example, if you have a very high Q value (many products vs. little reactants), the delta G may be positive (not spontaneous).

[BritneyP- 2c]

It should be spontaneous most of the time because you are releasing heat, and gas has more disorder to it. But i wouldn't say it is spontaneous all the time.

[Cooper Baddley 1F]

Hard to say something is always spontaneous but most of the time it will be

[kendal mccarthy]

I think most combustion reactions are spontaneous because they are exothermic, releasing heat, and usually cause an increase in gaseous substances, which have a higher value for entropy. It really depends on other determining factors, however.

[Rohit Ghosh 4F]

The way you can be completely sure that the reaction is spontaneous is by looking at the equation: G = H - TS. Because H will most likely be negative and S will be positive, combustion usually is spontaneous.

[ValerieChavarin 4F]

In the case of ∆G° = ∆H° - T∆S°, which indicates standard condition yes. The combustion of gas will be spontaneous due to the negative enthalpy value, the release of heat through an exothermic reaction, and a positive (increasing) entropy.